An 11-year-old girl doesn’t want her mother to return to Japanese as she awaits sentencing in Brisbane for a fatal arson attack on her husband.

An 11-year-old girl fears her husband-killer mother could harm her if she is freed to return to Japan, a court has been told.

The girl’s mother Sakura Suda, 45, has pleaded guilty to the manslaughter of her separated husband Kenji Suda, a Japanese national, in late 2011.

The girl returned to live in Japan with her paternal grandmother before the death. The elderly woman was also present in the Supreme Court in Brisbane on Monday.

In a sentencing submission, Crown prosecutor Brendan Campbell read out a victim’s impact statement, which outlined the girl’s fears of her mother returning to Japan.

“She does not want her mother to return and is worried the accused will turn up and do something,” he told the court.

Suda sobbed as a translator described her daughter’s dislike of her mother, and the girl’s traumatic experience of returning to Japan to live with her 81-year-old grandmother.

But defence barrister John Allen said Suda would be unlikely to reoffend, asking Justice David Jackson to take into account her mental illness at the time of the fire.

“There’s an identifiable mental illness which is treatable,” he said, adding the judge should also take into account her early guilty plea, genuine remorse, absence of any previous criminal history and the fact she was badly burnt during the arson attack.

Suda is accused of dousing her husband in petrol and setting him alight at his Runcorn home, in Brisbane’s south, on December 27 2011 – two months after they officially separated.

She was originally charged with the ferry skipper’s murder but the charged was downgraded to manslaughter in the Mental Health Court.

Suda has pleaded guilty to manslaughter and arson.

The court also heard details of Mr Suda’s long-standing extra-martial affair and of the accused’s relationship with a younger man whom she met during a 2010 holiday to Japan.

After their separation, Mr Suda bought his own unit, but let his separated wife move in that November when it became clear she couldn’t cope on her own, Mr Campbell said.

The prosecutor said the man had become increasingly concerned about his wife’s mental state and on December 21 sent his daughter to Japan.

Four days later, on Christmas Day, Suda filled two fuel cans at a service station and hid them in the spare bedroom, and on Boxing Day purchased matches, the court heard.

The next night neighbours heard screaming coming from the burning home.

Suda escaped by jumping from an upstairs window and landing on a hedge.

She suffered injuries from the fall and substantial burns.

Suda has already served two years and two months in pre-sentence custody.

Justice Jackson adjourned the hearing for a sentencing on Tuesday.